Storybook is a frontend workshop for building user interface components and pages in isolation.
CVE-2026-114126
Summary: The Storybook dev server exposes its WebSocket authentication token to any client that can load its HTML pages. Any host on a LAN can open a Storybook app by IP address, and therefore obtain the token. The WebSocket can be used to inject code into story files or to create new files. Under the right circumstances, an attacker can execute code on the machine of a developer connected on the same LAN. Who is impacted? You are impacted if you run a Storybook dev server whilst connected on an untrusted local network, or to a WiFi access point posing as a trusted network. The impact of this advisory is more important if you have the Vitest addon installed and are using an old version of Vitest. You are not impacted if: You run a dev server in an environment that other devices on your network cannot reach (e.g. a container that does not publish the Storybook port, or publishes it only on 127.0.0.1) You run a dev server whilst connected to a trusted local network You serve a built version of Storybook on your machine Recommended actions Upgrade Storybook Storybook has released patched versions of all affected major Storybook versions that fix all the vulnerabilities necessary for…
Part of the AI stack
This affects Model Context Protocol, in MCP & tool servers.
Assessment
- CVSS
- 8.7 (v4.0)
- Severity
- High
- EPSS
- 0.53% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 21 October 2026
- Last updated
- 28 October 2026
- Affected
- storybookjs · storybook · storybook · @storybook/core · @storybook/core-server · @storybook/experimental-addon-test
- Weakness
- CWE-1188, CWE-22, CWE-306, CWE-94
- Assigner
- security-advisories@github.com
CVSS vectorCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N
At the source
References
- https://github.com/storybookjs/storybook/commit/243c06bf8f1e2f09446c44868ea100261e1374da
- https://github.com/storybookjs/storybook/commit/3be03ec6f11f4616471cebc3fc65c13e1bf8c178
- https://github.com/storybookjs/storybook/commit/5540f03b209cc56c66f56a9c7cb4b2ee5b883ce5
- https://github.com/storybookjs/storybook/commit/a9ef9345d73224c73e0b81dc2701ec5b465ea9bb
- https://github.com/storybookjs/storybook/commit/d9b09e332510a88689c71ecc081bbbc2d072476e
- https://github.com/storybookjs/storybook/commit/df3fed468c9b4830605f00068c4bc6b7e1e215ed
- https://github.com/storybookjs/storybook/pull/36726
- https://github.com/storybookjs/storybook/releases/tag/v10.6.2
- https://github.com/storybookjs/storybook/releases/tag/v11.0.0-alpha.6
- https://github.com/storybookjs/storybook/releases/tag/v8.6.19
- https://github.com/storybookjs/storybook/releases/tag/v9.1.21
- https://github.com/storybookjs/storybook/security/advisories/GHSA-px85-f4q5-jh77
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Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-114126